Genealogies: unpacking the photographic collection of a Natal Midlands farming family (1905 – 1950)

This research explores a collection of family photographs from rural KwaZulu-Natal, South Africa, belonging to the white, English-speaking, Fyvie family. I concentrate on a subset of photographs from the first half of the 20th Century, during which time the family lived on a farm outside of Estcourt, a small agricultural town. This part of the collection is both geographically specific (marking decades passed in a single location), and temporally significant (coinciding roughly with the lead up to, and years of, the Union of South Africa). As such it offers insight into a discrete social microcosm during a particular historical period. What emerges from this study is a strong sense of local identification—a connection to a specific place, and to select people (family, community) in that place—that was nevertheless entangled with broader developments, including aspects of colonial nationalism within the context of the newly formed South Africa, concerns around health and degeneration arising in Europe, developments in scientific farming, and shifting attitudes toward gender. This fragile and dispersed sense of belonging was expressed through an alignment with certain groups of people and ideologies, but also asserted in relation to other groups, most notably black South Africans and, to an extent, Afrikaans-speaking South Africans, and ‘poor whites.’Dutch Research Council (NWO)Global Challenges (FSW

An Interpretive Systems View of Knowledge Investments

Viewing organizations as open, knowledge-dependent interpretation systems and building on the knowledge-based view, we develop a theoretical model of knowledge investments and value creation. By emphasizing the interpretive nature of organizations and examining knowledge requirements, capabilities, and investments, our contribution provides a more complete understanding of why some organizations make certain types of knowledge investments more than others and why these investments may have positive or negative effects on value creation.

Animal welfare and the use of procedural documents: Limitations and refinement

Increased scrutiny of animal welfare in wildlife management has seen a recent proliferation in the use of procedural documents (standard operating procedures, codes of practice etc.). Some procedural documents are presumed to represent 'best practice' methods, whereby adherence to prescribed inputs is explicitly purported to generate humane outcomes. However, the relationship between what is done to animals (inputs) and what they experience (outputs), as assessed by animal-based measures, has received little attention. Procedural documents are commonly developed in the absence of empirical animal-based measures, creating uncertainty in animal welfare outcomes. Prescribed procedures are valuable as guidelines for standardising methodology, but the development of 'welfare standards' that focus on desired thresholds for animal-based measures offers many advantages for improving animal welfare. Refinement of the use of procedural documents in wildlife management is required to ensure they generate desirable outcomes for animals, and do not preclude the development of improved methods

On slip pulses at a sheared frictional viscoelastic/ non deformable interface

We study the possibility for a semi-infinite block of linear viscoelastic material, in homogeneous frictional contact with a non-deformable one, to slide under shear via a periodic set of ``self-healing pulses'', i.e. a set of drifting slip regions separated by stick ones. We show that, contrary to existing experimental indications, such a mode of frictional sliding is impossible for an interface obeying a simple local Coulomb law of solid friction. We then discuss possible physical improvements of the friction model which might open the possibility of such dynamics, among which slip weakening of the friction coefficient, and stress the interest of developing systematic experimental investigations of this question.Comment: 23 pages, 3 figures. submitted to PR

Nuclear shadowing at low Q^2

We re-examine the role of vector meson dominance in nuclear shadowing at low Q^2. We find that models which incorporate both vector meson and partonic mechanisms are consistent with both the magnitude and the Q^2 slope of the shadowing data.Comment: 7 pages, 2 figures; to appear in Phys. Rev.

A threshold phenomenon for embeddings of H0mH^m_0 into Orlicz spaces

We consider a sequence of positive smooth critical points of the Adams-Moser-Trudinger embedding of $H^m_0$ into Orlicz spaces. We study its concentration-compactness behavior and show that if the sequence is not precompact, then the liminf of the $H^m_0$-norms of the functions is greater than or equal to a positive geometric constant.Comment: 14 Page

Quasi-particle model for lattice QCD: quark-gluon plasma in heavy ion collisions

We propose a quasi-particle model to describe the lattice QCD equation of state for pure SU(3) gauge theory in its deconfined state, for $T \ge 1.5T_c$. The method involves mapping the interaction part of the equation of state to an effective fugacity of otherwise non-interacting quasi-gluons. We find that this mapping is exact. Using the quasi-gluon distribution function, we determine the energy density and the modified dispersion relation for the single particle energy, in which the trace anomaly is manifest. As an application, we first determine the Debye mass, and then the important transport parameters, {\it viz}, the shear viscosity, $\eta$ and the shear viscosity to entropy density ratio, $\eta/{\mathcal S}$. We find that both $\eta$ and $\eta/{\mathcal S}$ are sensitive to the interactions, and that the interactions significantly lower both $\eta$ and $\eta/\mathcal S$.Comment: 10 pages, 8 figures, epj class file, version accepted for publication in Euro. Phys.J

Nonperturbative \gamma^* p Interaction in the Diffractive Regime

One of the challenging aspects of electroproduction at high-energy is the understanding of the transition from real photons to virtual photons in the GeV^2 region. We study inclusive electroproduction on the proton at small x_B using a nonperturbative dipole-proton cross section calculated from the gauge invariant gluon field correlators as input. By quark-hadron duality, we construct a photon light cone wave function which links the ``hadronic'' behavior at small Q^2 to the ``perturbative'' behavior at large Q^2. It contains quark masses which implement the transition from constituent quarks at low Q^2 to current quarks at high Q^2. Our calculation gives a good description of the structure function at fixed energy for Q^2<=10 GeV^2. Indications for a chiral transition may already have been seen in the photon-proton cross section.Comment: 28 pages, LaTeX, eps

Shadowing in Inelastic Scattering of Muons on Carbon, Calcium and Lead at Low XBj

Nuclear shadowing is observed in the per-nucleon cross-sections of positive muons on carbon, calcium and lead as compared to deuterium. The data were taken by Fermilab experiment E665 using inelastically scattered muons of mean incident momentum 470 GeV/c. Cross-section ratios are presented in the kinematic region 0.0001 < XBj <0.56 and 0.1 < Q**2 < 80 GeVc. The data are consistent with no significant nu or Q**2 dependence at fixed XBj. As XBj decreases, the size of the shadowing effect, as well as its A dependence, are found to approach the corresponding measurements in photoproduction.Comment: 22 pages, incl. 6 figures, to be published in Z. Phys.

Color Transparency versus Quantum Coherence in Electroproduction of Vector Mesons off Nuclei

So far no theoretical tool for the comprehensive description of exclusive electroproduction of vector mesons off nuclei at medium energies has been developed. We suggest a light-cone QCD formalism which is valid at any energy and incorporates formation effects (color transparency), the coherence length and the gluon shadowing. At medium energies color transparency (CT) and the onset of coherence length (CL) effects are not easily separated. Indeed, although nuclear transparency measured by the HERMES experiment rises with Q^2, it agrees with predictions of the vector dominance model (VDM) without any CT effects. Our new results and observations are: (i) the good agreement with the VDM found earlier is accidental and related to the specific correlation between Q^2 and CL for HERMES kinematics; (ii) CT effects are much larger than have been estimated earlier within the two channel approximation. They are even stronger at low than at high energies and can be easily identified by HERMES or at JLab; (iii) gluon shadowing which is important at high energies is calculated and included; (iv) our parameter-free calculations explain well available data for variation of nuclear transparency with virtuality and energy of the photon; (v) predictions for electroproduction of \rho and \phi are provided for future measurements at HERMES and JLab.Comment: Latex 57 pages and 17 figure